The Aurora Borealis is most visible during the winter months. Approaching the Arctic, these months are typically from December to March, and it is during this period that the hours of darkness are greater and the hours of daylight fewer. Lights may dance through the sky in shades of orange, yellow, green or red, or they may simply move through the sky in a single color for a shortened period of approximately 15 minutes.
Eskimo lore holds that the lights originate in either of two ways: spirits tossing a whale skull through the sky; or ghosts carrying people into the afterlife. Wisconsin’s Fox group of Native Americans often considered the lights to be defeated enemies rising up; this was an omen of war. The Eskimos of Greenland, however, held that the lights were the dances of children who had died before they had a chance to live.
According to the University of Alaska at Fairbanks’ Geophysical Institute, the Northern Lights are caused by energized protons in the Earth’s magnetosphere, a magnetic field that surrounds the Earth, which interact with the outer atmosphere of the sun. The sun’s own heat causes an outward projecting of protons and electrons known as plasma. When this solar wind encounters the Earth’s magnetosphere, that magnetosphere bends until it has to absorb those protons and electrons from the sun into the planet’s upper atmosphere. This is the Aurora Borealis.
Basically, the altitude of the light emissions and the density of the Earth’s atmosphere determine what colors will be seen in the night sky. When the protons and electrons absorbed into the planet’s upper atmosphere move at accelerated speeds, they send out photons with specific energies. The energy of these photons determines the color of the aurora. In the upper atmosphere are regular air, atomic oxygen and nitrogen. Oxygen atoms, for example, tend to give off light in either green or dark red hues.
